package com.tanxiuxin.YiWaiMai.filter;


import com.alibaba.fastjson.JSON;
import com.tanxiuxin.YiWaiMai.common.BaseContext;
import com.tanxiuxin.YiWaiMai.common.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.util.AntPathMatcher;


import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 *    过滤器 ： 用来检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter" , urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    // 路径匹配器
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        // 1. 获取本次请求的 URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}" , requestURI);

        // 1. 定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/shoppingCart/**"
        };

        // 2. 判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        // 3. 如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求不需要处理" , requestURI);
            filterChain.doFilter(request , response);
            return;
        }

        // 4-1. 网页端 判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee") != null ){
            log.info("用户已经登录，用户的ID为：{}" , request.getSession().getAttribute("employee") );

            Long empId = (Long)request.getSession().getAttribute("employee");
            // 这里是通过 TreadLocal 的特性，通过线程传递参数，请求都同属于同一个线程
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request , response);
            return;
        }

        // 4-2. 移动端 判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null ){
            log.info("用户已经登录，用户的ID为：{}" , request.getSession().getAttribute("user") );

            Long userId = (Long)request.getSession().getAttribute("user");
            // 这里是通过 TreadLocal 的特性，通过线程传递参数，请求都同属于同一个线程
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request , response);
            return;
        }

        log.info("用户未登录...");
        // 5. 如果未登录则返回登录页面, 通过输出流方式，向客户端响应数据
        response.getWriter().write(JSON.toJSONString(Result.error("NOTLOGIN")));
    }

    /**
     *      判断本次请求是否需要放行
     * @return
     */
    public boolean check(String[] urls , String requestUrI){
        for ( String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestUrI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
